Appendix to paper Assessment of tree layer biomass and structure using aerial photos in lake catchments of the Šumava Mts.: Figures in color

K. Matějka: JOURNAL OF FOREST SCIENCE, 55, 2009 (2): 63–74

Fig. 1. Program PlotOA – an example of the bitmap analysis window employed to measure the tree crown diameter. Values
in part A are decided to setting (weights of single colour channels, intervals of their permissible values, index – power value
(á) of the equation (1). Graph (B) shows variances of single colour channels (curves r, g, b), total variance – L variable defined
by equation (2) and gradient of total variance. An equalized bitmap slice can be visible in part C: black pixels are too dark for
analysis – their grey colour values are out of the set intervals. The fitted circle is drawn. Buttons in part D serve for a shift of border points of the interval within which the limit diameter should be calculated

Fig. 1a. The original bitmap slice of the orthophoto analyzed in the example of Fig. 1. It can be shown in the bitmap analysis
window after the switch button pressing

Fig. 2. Catchment of the Plešné jezero Lake with sample squares (50 m × 50 m in size) classified according to Clark-Evans’ statistics. The position of each tree in the sample square is indicated by a small cross. Terrain elevation is indicated by contour lines with 10 m interval

Fig. 3. Catchment of the Čertovo jezero Lake with sample squares (50 m × 50 m in size) classified according to Clark-Evans’ statistics. The position of each tree in the sample square is indicated by a small cross. Terrain elevation is indicated by contour lines with 10 m interval